The present invention relates to self-assembly of organic molecules and, more particularly, to self-assembly of a cationic porphyrin and an anionic porphyrin to form a clover-like biomorphic structure.
Nanostructures self-assembled from organic molecules are of great interest because of their potential applications in areas such as organic photovoltaics and electronics, sensors, nonlinear optics, and catalysis. These nanostructures also offer opportunities for mimicking the processes that occur in biological photosynthesis to produce fuels, and this is especially true when the organic molecular subunits of the nanostructures are porphyrins. Herein, we describe some extraordinary porphyrin biomorphs (biomorphs are structures that are shaped like living organisms) obtained by the self-assembly of two oppositely charged porphyrin ions (tectons). Significantly, the overall shape and size of these biomorphs appears to be largely independent of the metal complexed to the porphyrin. As the metal-centered interactions determine the electronic characteristics of the porphyrin macrocycle (e.g., electron donor versus acceptor), simply altering the metals in the porphyrin tectons provides a high degree of control over the cooperative interactions between the tectons (e.g., charge transfer) and thus the functionality of the organic solid (e.g., charge separation and migration).